This invention relates to video compression techniques, and more particularly, to video compression techniques suitable for use with three-dimensional content such as three-dimensional virtual reality environments.
With the increasing popularity of network-based applications, compression of synthetic animation image sequences for efficient transmission is more important than ever. For long sequences, the latency time of downloading the compressed file may be prohibitive, even if the overall compression ratio is high. A better network-based compression scheme may involve partitioning the compressed sequence into two parts. The first part, or header, may be small enough to be downloaded within an acceptable initialization time, while the second part may be transmitted as a stream. The compressed data may be broken up into a stream of data that may be processed along the network pipeline--i.e., the compressed data may be transmitted from one end and received, decoded, and displayed at the other end. Streaming necessarily requires that all the pipeline stages operate in real time. Network bandwidth is the most constrained resource along the pipeline. The main challenge is therefore to reduce the stream bandwidth enough to accommodate the network bandwidth constraint.
Standard video compression techniques like MPEG, are generally insufficient for steaming in low-bandwidth environments. For example, average MPEG frames are typically about 2-6K bytes in size for moderate frame resolutions. Assuming a network with a sustained transfer rate of 2K bytes per second, a reasonable quality of a few frames per second cannot be achieved.
A significant improvement in compression ratio is still necessary for streaming video in real time.
It is an object of the present invention to provide improved video compression schemes.
It is a further object of the present invention to provide video compression schemes that allow high-quality content to be streamed over relatively low-bandwidth network connections.